Apparatus for forming spring liners



March 7, 1961 c, s, REED 2,973,788

APPARATUS FOR FORMING SPRING LINERS Filed May 15, 195'? INVENT OR.

CA /i/A? 6. R550 BLM/d@ PMM United States Patent O 2,973,788 APPARATUS FOR FORMING SPRING LINERS Clair S. Reed, Wayne, Mich., assignor to Van Dresser Specialty Corporation, Van Dyke, Mich., a corporation of Michigan Filed May 13, 1957, Ser. No. 658,857

3 Claims. (Cl. 14o-92.94)

This invention relates to an improved apparatus for fabricating wire reinforced sheet material adapted to serve as a cover or liner for upholstery springs and the like.

It is common practice in the upholstery industry to provide spring liners or covers which are disposed on top of upholstery springs underneath the padding or cushioning material that overlies the springs. `Such spring liners prevent the padding from being wedged down between the springs. vSuch a liner is commonly in the form of a sheet of suitable sheet material reinforced with wire or the like. The sheet may be formed of fabric such as burlap, which fabric has been reinforced with spring wires extending therethrough and disposed generally within the plane thereg of or overlying the4 fabric and attached thereto.

This invention pertains to the art of fabricating a spring liner of the character described and particularly to one such as is shown in my copending application Serial No. 613,224, filed October l, 1956, now Patent No. 2,906,320. This invention pertains to an improved apparatus for fabricating a ,spring liner of the character described. It relates particularly to fabricating a spring liner comprising a sheet of burlap or other suitablel sheet material reinforced with wire helices threaded therethrough, with the sheet material of the liner extending substantially diametrically of the convolutions of the wire helices after the latter have been threaded entirely through the sheet material from opposite sides thereof.

An object is to provide an improved apparatus for inserting or threading reinforcing wires at spaced intervals through a sheet of suitable material such as burlap.

Another object is to provide an improved apparatus for inserting or threading reinforcing wires through a strip of perforable sheet material such as fabric woven from fibers or plastic filaments, and for doing so rapidly, cheaply, and accurately, and in such a manner that the wires will normally retain their position within the strip.

Another object is to provide improved apparatus adapted to be used in the insertion of reinforcement wires through a strip as hereinabove specified, which apparatus is simple and inexpensive and adapted to form the wire for ready insertion or threading and to insert the wire through the strip as desired.

More specifically an object is the provision of a improved apparatus for inserting reinforcing strands of wire through a perforable sheet which comprises forming a wire into a cylindrical helix and rotatably advancing the formed helix axially and within the plane of a supported sheet of liner forming material so that the helix is spun or threaded through the sheet to form a helical reinforcement Wire extending through the sheet and disposed substantially within the plane thereof.

Other objects, advantages, and meritorious features of this invention will be made more apparent as this description proceeds, especially when considered in connection with the accompanying drawing wherein:

Fig. 1 is a diagrammatic cross sectional view through apparatus adapted to carry out the process of the invention;

i 2,973,788 Patented Mar. 7, 1961 ice Fig. 2 is a cross sectional View taken on the line 2-2 of Fig. 1;

Fig. 3 is a plan of a strip of fabric provided with the reinforcement wires of this invention.

Fig. 4 is a fragmentary vertical sectional view taken on the line 4-4 of Fig. l.

In applicants copending application supra, a spring liner is shown which embodies the structure that results from employing the apparatus herein described. Such structure comprises a sheet of flexible material reinforced with cylindrical wire helices threadedtransversely therethrough from opposite sides thereof, so that portions of the convolutions of the wire helices are disposed upon and project from opposite sides of the sheet material. vThe spring liner sheet-may be of any suitable cheap, strong, flexible, perforable material such as a fabric woven from fibers or plastic filaments. Wherever throughout the speciication and claims; the word fabric is used to charterize the sheet, rit is understood that a suitable spring liner sheet fabricated in any manner is intended. ln Fig. 3 the fabric sheet is shown in the form of a strip lindicated as 10, and successive Wire helices are indicated as 12. Preferably the-wire helices are threaded through a linear stripvof fabric assho-wn. Such strip is thereafter cut into lengths suitable for use as spring liners for upholstery springs. The fabrication is more or less a continuous operation with the fabric strip, being moved along Vintermittently linearly, yand the wire helices threaded therethrough during the interruptions of such movement. The drawin-gillustrates schematically an apparatus for fabricating such a spring liner.

In Figs. 1 and 2 a pair of clamping and supporting guide plates 14 and 16 are shown. These plates are adaptedto be moved toward and away from eachother to 4grip the sheet 10 therebetween. This sheet can be advanced along inA anysuitable conventional manner Vand its alvan'ceing terrupted' when the sheet is'gripped bythe plates.l i

Each plate is formed to define one-half of la pass-ageway 17 as shown in Figs. 1 and 2. Each plate is provided with a groove or channel 18 vwhich constitutes one-half of the passageway 17. These channels 18 are complementary. When the -tWo channels 18 are superposed they constitute a complete passageway 17. This passageway 17 is of a size to receive and support for axial advance therethrough a cylindrical helix 20 of spring wire. The passageway 17 may be of any desired cross sectional shape. As shown it is square and guides the advance of the helix therethrough while offering a minimum frictional resistance to such advance. The helix 20 is here shown as a cylindrical helix circular in cross sectional shape. Any shape of wire helix suitable for threading through the sheet as shown might be employed.

In Fig. 1 there is shown a pair of feed rolls 21 and 22 which may be driven in any suitable manner to advance a wire strand 24 lengthwise therebetween. This wire strand is adapted to be advanced through a helix-forming die assembly 26. This die structure is conventional. The wire strand is advanced through a passageway in a part 27 until it contacts `a sloping shaping surface 28 and is guided thereby to encircle a mandrel 29 as shown in Fig. 1. Such helix formation is conventional. So fabricated, the wire is in the form of a cylindrical coil or helix which might be of any suitable cross sectional shape.

This formed wire coil or helix is advanced axially through the passageway 17 formed between the two plates 14 and 16. As it is axially advanced it is rotated about its axis. This rotation results from the motion given to it in its shaping. It might, of course, be preformed and otherwise rotated 'and advanced. As it is passed through the passageway 17, its leading free end is needled through the fabric sheet stretched across the passageway, and the convolution of. the helix is threaded through the sheet" from opposite sides thereof as shown in Fig. l. It is apparent that the convolutions of the wire helix are threaded through the sheet through successive linearly spacedpoints and therefore areretained against -li'nea'r` displacement fr'om the sheet`mate rial 10.

Cutting` means in' the form' of knives 30 maybe" provided to` sever a helix`20aft`er it has` been moved through the strip. It is apparent that' the structure' shown might bey duplicated any de sired number of| times' so that:- any desired number'of wife helices might be advanced simultaneouslythrough' a'strip of fabric. It is also apparent thatV the-severingjmechanism might include knotting'means to` knot the endof the wire if desired.

WhatI claii'n is:

l'. Apparatus' for making a wire helix reinforced sheet adapted to serve as a' co'ver'for` upholstery springs; comprising a' pair ofi verticallyy opposed substantially horizontal plates, o'ne being, movable vertically' toward,` and away from the other,.said` plates being provided with vertically opposed substantially at surfaces operable when said movable plate is moved vertically away from the other plate to permit advancement edgewisetherebetween in a horizontal plane of a sheet of exible` sheet material, and operable when said movable plate is moved vertically toward the other platev to grip and hold said sheet in a predetermined horizontal position, said opposed substantially flatsu'rfaces having therein transverse; ly extending vertically' opposed complementary grooves of substantially V shape in cross section provided with opposedsubstantially hatI walls and adapted when said movablev plate is moved toward the other plate to form an; open ended'substantially straight passageway of substantially square cross section throughout the length'of which a-rotatingrsubstantially cylindrical wire helix having a leading free end and successive convolutions following said leading free end may be advanced, and means spaced frornsaid plates substantially in alignment with said passageway and operable when said sheet is gripped by said plates to` form, rotate, and advance said wire helix lengthwise of said passageway to be threaded through said gripped sheet, the opposed substantially flat walls of said grooves being tangentially engaged by diametrically opposite sides only of said cylindrical wire helix during rotation of said helix as it is advanced through said passageway, said sheet extending across and substantially coinciding with the longitudinal center of saidl passageway when said sheet is gripped by said plates, andthe' axis of said helix being coincident withthe"horizontalf plane ofA saidv grippedV sheetr throughout the travel of said helix lengthwise of said" passageway, whereby the leading free end and successive convolutionsofsaid helix are threadedV successively through said sheet from opposite surfaces thereofA to be connected therewith at linearly spaced points thereof to provide ah'elix reinforced sheet wherein said sheet extends substantially diametrically of the convolutions connected thereto.

2. The apparatus described in claim l.; wherein the passageway forming grooves extend at` substantially right angles'to the direction of edgewi'seA advancement of4 said sheet,` andthe substantially fiat walls of said grooves constitute guidesfr the leading fr'ee` end and the convolutionsof said wire helix as the latterl is advanced throughout the length ofsaid passageway tobe threaded through said'sheetl v 3; The apparatus described in clai'm' 1; comprising means between the forming means aforesaid' and said platesA for severing the wire of'an unthr'eaded'formed portion of said helixVA aftera predetermined length o'f` said formed'helix hasfb'een threaded through and connected to said sheet a't'linearly'spac'ed pointsthe'reof.

References C'itdlin the 1eofthispatenr UNITED STATES PATENTS 

